Grass-ski

ABSTRACT

A ski structure is provided including a frame which includes a pair of rigid side plates, a plurality of reinforcing strut members extending between said side plates, and a support platform extending between said side plates, and a plurality of wheel assemblies secured to and extending between said side plates and longitudinally spaced therealong.

United States Patent [1 1 Birnbaum et al.

[ 1 Dec. 2, 1975 I 1 GRASS-SKI [76} Inventors: Richard S. Birnbaum, 111E. 64th Ave., Philadelphia, Pa. 19120; Bruce H. Birnbaum, 13540Youngwood Turn, Bowie, Md. 20715 [22] Filed: Dec. 27, 1973 [21] Appl.No.: 428,711

[52] US. Cl. 280/11.22

[51] Int. Cl. A63C 17/04 [58] Field of Search..... 280/11.22, 11.1 BT,11.1 R,

[56] References Cited UNITED STATES PATENTS 880,519 3/1908 Graffenberger280/7.l3 954,993 4/1910 Peters 280/11.22 X 1,428,210 9/1922 Boche 280/11.22

1,801,205 4/1931 Miriclc 280/1122 X 2,644,692 7/1953 Kahlert 280/11.223,282,598 ll/1966 Goodwin 280/11.22 X 3,722,900 3/1973 Dickert 280/11.1BT X FOREIGN PATENTS OR APPLICATIONS 453,425 9/1936 United Kingdom280/l1.22 247,346 10/1963 Australia 280/11.1 BT

Primary ExaminerRobert R. Song Attorney, Agent, or FirmFidelman, Wolffe& Leitner [57] ABSTRACT A ski structure is provided including a framewhich includes a pair of rigid side plates, a plurality of reinforcingstrut members extending between said side plates, and a support platformextending between said side plates, and a plurality of wheel assembliessecured to and extending between said side plates and longitudinallyspaced therealong.

6 Claims, 6 Drawing Figures US. Patent Dec. 2, 1975 Sheet 1 of23,923,316

I :0 F103 A v ZL////// US. Patent Dec.2, 1975 Sheet 2 of2 3,923,316

SAMPLE 1 SAMPLE 2 8m U. U

GRASS-SKI BACKGROUND OF THE INVENTION It is another object of theinvention to provide a means to permit ski resorts to operate throughoutthe entire year.

It is a further object to enable the beginner to learn to ski moreeasily because the skier automatically develops the technique ofparallel skiing.

It is still another object to provide means for skiing on grass usingconventional ski equipment such as ski boots and bindings.

It is another object of the invention to make possible the enjoyment ofthe sport of skiing in areas never before possible because cold weatherand snow are not necessary in the practice of the instant invention.

These, together with other objects and advantages which will becomeapparent in the details of construction and operation are more fullydescribed and claimed hereina ter.

For a more detailed description of the invention, reference is made tothe following specification and drawings in which:

FIG. 1 is a side elevational view of the ski;

FIG. 2 represents a bottom plan view of the ski shown without wheels;

FIG. 3 represents a partial bottom plan view showing the placement ofwheels and spacers on the individual axles;

FIG. 4 is an enlarged partial plan view of the wheel and axle assembly;

FIG. 5 is a perspective view of one embodiment of the ski showing samplesupport struts and axle mountings; and

FIG. 6 shows a few modified wheel diameter and wheel assembly profilevariations without spacers.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The grass-ski unit includes aframe member 1, a plurality of wheel assemblies 2 and a ski boot holder3.

The frame 1 is constructed with side plates 4, struts 5 and a ski bootholder platform 6. The struts S are located at various points along theski to give the frame rigidity. The lower most struts, as seen in FIG.5, add this rigidity and substantiallyprevent cambering of the loweredge of the side plates. The over-all length of the ski may be varied toprovide the proper stability to keep the user from tipping over andfalling.

For a more detailed description of the wheel assemblies 2, reference ismade to the view of FIG. 4. An axle shaft 7 extends between alignedapertures in the side plates 4 perpendicular to the longitudinal axes ofthe ski. A fastener 8 and locking pin 9 serve to secure the axles 7 inposition. A plurality of cylindrical sectional wheels 10 are mounted onthe axle 7 and are separated from each other and the side plates 4 byspacer rings 1 1 FIG. 4) are located longitudinally along the length ofthe ski. The multiple wheel assemblies 2, provided with the spacers 11allow for slippage or different relative velocities between theindividual wheels 10 to allow the operator to turn and provide minimumfriction while in operation. The multiple wheel assemblies serve toprovide low friction movable support points that allow an operator tomove downhill at a high rate of speed unaffected by uneven surfaces inthe terrain.

The multiple wheel assemblies may be resiliently mounted between saidside plates through aligned elongated apertures in said side platesusing a resilient fastener and locking device. This mounting meansprovides for a slight vertical movement of the entire assembly, therebyfurther minimizing the effects of rough terrain.

The preferred number of wheel assemblies is generally less than 20; themost preferred number of wheel assemblies being between 8 and 16inclusive.

In the preferred embodiment, steel was chosen for strength and low costin construction of the frame and axles while nylon was chosen for thewheels and spacers to provide a tough abrasion and cut resisting surfacewhile at the same time being self-lubricating to enhance the low-fictioncharacteristics and requirements.

Alternate materials could be utilized in the construction of the frame.A few examples include reinforced plastic, cast or injection moldedplastic, aluminum alloys, mangesium alloys, copper alloys, and brass andstainless steel alloys. The wheels and spacers could also be made ofwood, steel or plastic and may not have separate sleeve bearings, ballbearings, or self-lubricating cast-in bearings.

The structural shape may be modified in length, width, number of axlesand wheels to provide different operating characteristics. In addition,as shown in FIG. 6, the diameters and end profiles of the wheels may bevaried along the axles to change the operating characteristics of theskis. The axles may be resiliently mounted in the side plates tominimize the effects of rough terrain, and may be uniformly spaced orgrouped along the length of the ski. The boot holder may be movedforward or back along the ski or sunken into the frame to providemodified operational characteristics.

The foregoing is considered as illustrative only of the principles ofthe invention. Thus, it is to be understood that changes andmodifications to the embodiments as illustrated and described may bemade without departing from the spirit of the invention or the scope ofthe appended claims.

What is claimed is:

l. A ski structure comprising a frame including a pair of rigid sideplates, a plurality of reinforcing strut members extending between saidside plates, and a support platform extending between said side plates,and a plurality of wheel assemblies secured to and extending betweensaid side plates and longitudinally spaced therealong, at least one ofsaid strut members located below the axis of rotation of said wheelassemblies and adjacent the lower edge of the side plates tosubstantially lindrical section and having a diameter less than thediameter of said wheels.

4. A ski structure of claim 2 wherein the diameters of the individualwheels may vary along the axles.

5. A ski structure of claim 2 wherein said axles are secured betweensaid side plates perpendicular to the longitudinal axis of said ski bymeans of a fastener and locking pin.

6. A ski structure of claim 1 wherein the plurality of wheel assembliescomprises at least three of said wheel assemblies.

1. A ski structure comprising a frame including a pair of rigid sideplates, a plurality of reinforcing strut members extending between saidside plates, and a support platform extending between said side plates,and a plurality of wheel assemblies secured to and extending betweensaid side plates and longitudinally spaced therealong, at least one ofsaid strut members located below the axis of rotation of said wheelassemblies and adjacent the lower edge of the side plates tosubstantially prevent cambering of the lower edge of said side plates.2. A ski structure of claim 1 wherein said wheel assemblies include anaxle, a plurality of independently rotatable wheels mounted thereon, anda plurality of spacers which serve to maintain separation between saidindividual wheels and said wheels and side plates, each of said spacershaving A width no greater than the width of each wheel.
 3. A skistructure of claim 2 wherein said wheels are cylindrical sectionalwheels and said spacers are of cylindrical section and having a diameterless than the diameter of said wheels.
 4. A ski structure of claim 2wherein the diameters of the individual wheels may vary along the axles.5. A ski structure of claim 2 wherein said axles are secured betweensaid side plates perpendicular to the longitudinal axis of said ski bymeans of a fastener and locking pin.
 6. A ski structure of claim 1wherein the plurality of wheel assemblies comprises at least three ofsaid wheel assemblies.